1. Field of Invention
Embodiments of the invention relate in general to multicasts. More specifically, the embodiments of the invention relate to multicast streaming in heterogeneous networks.
2. Description of the Background Art
Multiparty communication involves transmission of data to multiple receivers, which are connected to each other over a network. The network includes a source host that sends data packets to the multiple receivers identified by a single address. The technique for transferring data to multiple receivers simultaneously, by using the single address, is known as a multicast. A multicast can be used for streaming multimedia content to multicast receivers. For example, the multicast can be utilized in distant e-learning programs in which a video file is played at the source host and is viewed simultaneously by the multiple receivers that have made a request for it. Moreover, the multiple receivers can form a group known as a multicast group. The multicast group can have receivers with different available bandwidth to send and receive data. The multicast used for transmission of data to multiple receivers with different bandwidth availability is known as a heterogeneous multicast. However, in the heterogeneous multicast, the transmission rate of multimedia content is fixed, based on the lowest bandwidth available among the receivers in the multicast group. Many receivers with large bandwidth are not able to avail of good quality viewing or listening to multimedia stream, in spite of having sufficient bandwidth.
According to a conventional technique, layered encoding of multicast streams is used for better utilization of bandwidth in a heterogeneous multicast. In this technique, the receivers with low bandwidth receive fewer layers of encoded multicast stream. Fewer layers result in low quality of the multicast stream. In addition, clients at the receiving end of the multicast stream should be compatible, to decode the layered encoded data for streaming the multicast stream.
In another conventional technique, a video gateway is used, which can reformat the incoming multicast stream, based on varying bandwidth availability in the heterogeneous multicast. The multicast stream is divided into multiple sessions with different bandwidth requirements. The multiple sessions are connected into a single multicast stream by manipulating the data of the multicast stream in a session-transparent fashion.